Having a issue with my cherokee overheating, or just running really hot. Had a bad heater core replaced 3 days ago, no i have heat but jeep is acting like its overheating. Jeep warms up to 210 in about 10 mins. 1 heater hose is really hot to the touch other is cool. Then jeep temp climbs into the red,check guage light comes on and it runs there for awhile. Air from vents is cold, then the guage drops back to 210-215 and i get great heat from the vents. It will do this multiple times. Any ideas on what it could be?

the rad and water pump are only a yr old. When i got the jeep it had a radiator leak and someone put stop leak in it. I changed everything out then, and have replace the therostat and temp sending unit in the last day.

Pull the vac line going to the heater control valve and see if you get flow. The valve is on passenger side of the engine and has a small grey hose coming out of the firewall and going into a 4 way junction with a small solenoid on it.

I have a 96 and just the other day i touched the junction and it exploded. It was 16 years old.

It could be air bubbles in the cooling system or a sticky thermostat. Replace your thermostat. Use a top quality thermostat like a STANT or genuine Jeep.

1997-2001 do not have a heater control valve.

2000-01 have the 0331 head which is prone to cracking. Do a Google search.

Overheating can be caused by anything that decreases the cooling system’s ability to absorb, transport, and dissipate heat, such as a low coolant level, loss of coolant (through internal or external leaks), poor heat conductivity inside the engine because of accumulated mineral deposits in the water jackets or radiator, a defective thermostat that doesn’t open, poor airflow through the radiator, a slipping fan clutch, an inoperative electric cooling fan, a collapsed lower radiator hose, an eroded or loose water pump impeller or even a defective radiator cap.

The cooling system is a group of related parts that depend on proper function from each of its component parts to keep the engine cool. Service the cooling system and replace any under-performing or suspected weak parts. Any component part of the cooling system that is not fully doing its job will stress the others and your cooling system will overheat. Temperature creep on the 4x4 trails, at idle, or in stop-n-go traffic points to a weak or failing mechanical fan clutch.
The most important maintenance item is to flush and refill the coolant periodically. Coolant should be replaced every 36,000 miles, or every two to three years. Anti-freeze has a number of additives that are designed to prevent corrosion in the cooling system, but they have a limited life span. The corrosion causes scale that eventually builds up and begins to clog the thin flat tubes in the radiator and heater core, causing the engine to eventually overheat.

-Use a flushing/cleaning solution and then drain and fill the radiator with a fresh 50/50 coolant and water mix. With a neglected cooling system you may have to flush several times.
-Inspect the radiator for mud/bugs/grass clogging the outside and mineral deposits clogging the inside. Clean or replace as needed.
-Replace the thermostat with a STANT or Robertshaw 195* thermostat. Cheap thermostats are cheap for a reason.
-Replace the radiator cap if your Jeep has one. An old worn out cap will allow boil overs and/or allow the coolant flash over into to steam. You will see the coolant temps suddenly jump from 210* to the Red Zone and back to 210* if your radiator cap is weak.
-Inspect/test or replace the mechanical fan clutch. A worn fan clutch will allow temperature creep at stoplights, in heavy traffic, and on the 4x4 trails. A fan clutch that “looks” OK is not the same as working OK. Consider installing a Heavy Duty fan clutch such as the NAPA #272310.
-Inspect the electric cooling fan and the fan relay. Apply 12 volts and make sure the fan runs. Exchange the cooling fan relay with one of the others similar relays. Confirm that the e-fan starts when engine temps reach 215-218*. Repair or replace the fan or relay as needed.
-Inspect/test or replace the coolant temperature sensor that activates the e-fan.
-Replace the water pump. The pumping fins can deteriorate over time and the pump will not flow enough coolant to keep the temps under control.
-Inspect/replace the radiator hoses. Make sure the coiled wire is installed in the lower hose.

If you have covered all the points listed above and still have overheating issues, inspect the head for cracks and head gasket for leaks. Exhaust gasses entering the coolant can raise the temperature of the coolant or cause steam pockets in the coolant that will temporarily block the flow of coolant

What vacum line did you pull off because you do not have a heater control valve.I agree with Tim on either a stuck T Stat or air in your system.Did you do the Google search for 0331 cracked head if not you really should just so you understand that problem.First signs of a 0331 cracked head will be unexplained coolant loss which if not corrected very quickly will pretty much call for a engine rebuild.

Well looks like im pulling the head! Had a mechanic friend do some tests, and looks like its definitly head related. So im gonna pull the head and check the gasket on the head before i do anything else. Thanks for the info and help guys. Ill keep you guys posted, and asking questions along the way. I still love my jeep, but right now i dont like it very much. lmao!